This invention relates to a device and a method for detecting and mapping the diseased blind areas in a person's vision. The most widely used visual field tester today is the Standard Automated Perimeter (SAP) which is used to perform a contrast sensitivity test. In this test, a person is usually seated in front of a hemispherical projection surface whereupon an optical projection system projects circular spots according to an algorithm, and the subject responds to the stimulus by pressing an input device such as a mouse. Usually the algorithm used to project the spots of light is written so that the location and the timing of the projected lights are random to the user. This is to keep the user from falling into a rhythm and expectantly clicking on the input device even when he or she does not see the projected light. However, these SAP tests suffer from a number of disadvantages.                a) They are costly and most individuals would normally not be able to afford them. SAP equipment require an expensive projection system, software and hardware. The SAPs are usually only found at hospitals and eye physicians' offices. As a result, SAPs are not easily accessible devices. If someone wanted to monitor the condition of one's own visual field, he or she would not be able to run a visual field test often and usually would have to make an appointment with a doctor to do so.        b) SAPs are large bulky machines. They are not mobile machines that can be transported anywhere. Current SAPs are large and heavy and once they are placed at a certain location they cannot be moved easily.        c) SAPs are prone to inaccuracies and sometimes do not detect problems in the visual field until noticeable deterioration has occurred. One of the problems with SAPs is that due to the random generation of projected lights, users do not know where the next light will appear; therefore, sometimes they will often miss identifying certain lights because they were not prepared. The SAP tests are time-constrained; while a user is pondering whether or not to click the button, the next light appears. Therefore, it is a man-machine contest with the user being quite nervous in taking the test. Also, some machines require the user to fixate his or her eye on a bright light in order to keep the eye from wandering. However, blinking often creates after-images which tricks subjects into seeing a projected light where none was projected.        d) The result from SAPs do not show decisive results for each location in the visual field. Due to the inaccuracies in the SAPs, their algorithm usually displays or prints out a map of the visual field with each area of the visual field given different probabilities of damage or problems. This is done to account for the user's errors in clicking or identifying random lights. If the user did not click the button when a light was projected, the result from the SAP would be inaccurate. Rather than identifying an area where the subject could not see as a problem area, the SAP might identify it as an area with medium probability, but not definite probability.        e) Current visual field testers are not good at early detection of glaucoma or other eye diseases. If glaucoma can be detected early on, medication such as pressure-reducing eye drops can be given to stop the farther destruction of optical nerves in the eye. Often, when glaucoma is detected, excessive damage to the nerves in the eye has already occurred causing severe visual field loss. Because of the uncertain outputs from SAP testers, doctors and patients are often misled into believing glaucoma does not exist, when in actuality, it is already present. For example, a doctor may look at a result from a SAP and incorrectly conclude that an area with medium probability next to the natural blind spot is not problematic and is considered part of the natural blind spot when in reality, nerve cells have already begun to die in that region as is shown in the later section under the title “Accurate Detection of Diseased Blind Areas: FIGS. 6A-6B.”        